Chemical constituents from Tabernaemontana catharinensis root bark: a brief NMR review of indole alkaloids and in vitro cytotoxicity

This work describes the isolation and structural determination of pharmacological compounds present in the bark of roots of Tabernaemontana catharinensis (Apocynaceae). Among the 27 substances detected 12 were identified as terpenoid-indole alkaloids, 2 steroids and 13 pentacyclic triterpenes. Structures were outlined based on HMQC, COSY, DEPT, 13C, and ¹H NMR data and MS. Spectral data of indole alkaloids were reviewed. An in vitro screening of the extracts and isolated compounds was carried out. Compounds ibogamine (5), 3-oxo-coronaridine (9) and 12-methoxy-4-methylvoachalotine (MMV) demonstrated effective cytotoxicity towards SKBR-3 breast adenocarcinoma and C-8161 human melanoma tumor cell lines.

Estudo do comportamento do chumbo em latossolos brasileiros tratados com fosfatos: contribuições para a remediação de sítios contaminados

Phosphates have been used for lead immobilization in soils but the influence of soil type is not fully understood. In this work, lead chemical behaviour in two Brazilian latosoils (LA and LV) was studied via treatment with phosphates. The Pb concentration in Toxicity Characteristic Leaching Procedure (TCLP) solutions was decreased in all treatments. After treatment with H3PO4 the Pb concentration in the LA remained within the regulatory limit established by EPA. The ecotoxicological results with Daphnia pulex showed that this treatment reduced the lead bioavailability. Sequential extraction analyses showed that the lead was transferred from the most available to the residual fraction. Relevant decrease of soluble lead was observed in all phosphate treatments.

Avaliação das técnicas de precipitação química e encapsulamento no tratamento e destinação conjunta de resíduos líquidos contendo cromo e vidrarias de laboratório

In this paper, we present procedures for the treatment and final disposal of residual solutions containing chromium, in order to evaluate the effectiveness of chemical precipitation of the metal and the potential of the glass encapsulation technique, using broken laboratory glassware. The results demonstrated that pH-values convenient for chemical precipitation are between 10 - 11. With regard to Cr(OH)3 encapsulation, the leaching and solubilization tests allowed to classify the waste as non-dangerous and non-inert. Finally, it is pointed out that the adoption of waste management practices in universities should be encouraged, helping to train professionals skilled in good laboratory practices.

Sampling in chemical analysis

The uncertainty of any analytical determination depends on analysis and sampling. Uncertainty arising from sampling is usually not controlled and methods for its evaluation are still little known. Pierre Gy’s sampling theory is currently the most complete theory about samplingwhich also takes the design of the sampling equipment into account. Guides dealing with the practical issues of sampling also exist, published by international organizations such as EURACHEM, IUPAC (International Union of Pure and Applied Chemistry) and ISO (International Organization for Standardization). In this work Gy’s sampling theory was applied to several cases, including the analysis of chromite concentration estimated on SEM (Scanning Electron Microscope) images and estimation of the total uncertainty of a drug dissolution procedure. The results clearly show that Gy’s sampling theory can be utilized in both of the above-mentioned cases and that the uncertainties achieved are reliable. Variographic experiments introduced in Gy’s sampling theory are beneficially applied in analyzing the uncertainty of auto-correlated data sets such as industrial process data and environmental discharges. The periodic behaviour of these kinds of processes can be observed by variographic analysis as well as with fast Fourier transformation and auto-correlation functions. With variographic analysis, the uncertainties are estimated as a function of the sampling interval. This is advantageous when environmental data or process data are analyzed as it can be easily estimated how the sampling interval is affecting the overall uncertainty. If the sampling frequency is too high, unnecessary resources will be used. On the other hand, if a frequency is too low, the uncertainty of the determination may be unacceptably high. Variographic methods can also be utilized to estimate the uncertainty of spectral data produced by modern instruments. Since spectral data are multivariate, methods such as Principal Component Analysis (PCA) are needed when the data are analyzed. Optimization of a sampling plan increases the reliability of the analytical process which might at the end have beneficial effects on the economics of chemical analysis,

Passeig per l’invisible: itinerari químic per la ciutat de Girona = A walk through the invisible: a chemical journey through Girona

The presented itinerary covers eleven sites of the city of Girona that have been chosen for their interest from a chemical point of view. Girona is a city with chemistry, and this journey allowed student to see that chemistry is present everywhere, even in everyday life and not only in classrooms and laboratories. This approach aims to motivate students to discover something that had been invisible

Caracterização e classificação de resíduo sólido "pó de rocha granítica" gerado na indústria de rochas ornamentais

The ornamental rock industry generates huge amounts of wastes during the process of extraction and sawing of rock blocks. The ornamental rock powder waste is a non-biodegradable material, which represents the increase in environmental problem. The waste was collected from a granitic rock sawing plant located in Santo Antônio de Pádua, Rio de Janeiro. The chemical-environmental characterization and classification of the waste were done according to ABNT standards. The results showed that the granitic rock powder waste should be classified as Class II A - "No Inert", because of its high concentrations of lead, chrome, iron and manganese.

Chemical composition and antimicrobial activity of the essential oil of Hyptis pectinata (l.) Poit.

Essential oil was extracted from leaves of Hyptis pectinata using hydrodistillation, and its composition determined using GC-FID and GC-MS. Chemical analysis showed that there was a predominance of sesquiterpenes, of which β-caryophyllene (18.34%), caryophyllene oxide (18.00%) and calamusenone (24.68%) were measured for the first time in the genus Hyptis. Twenty-one compounds were identified, and calamusenone was isolated using preparative thin layer chromatography with a silica gel plate (60 PF254). The minimal inhibitory concentration (MIC) and minimal microbicidal concentration (MMC) were determined for various pathogenic microorganisms. H. pectinata oil was most effective against Gram (+) bacteria and yeasts.

Chemical composition and analgesic activity of the leaves and branches of Marlierea tomentosa Camb.

This paper describes the isolation of five phytoconstituents from Marlierea tomentosa. The triterpenes α-amyrin (1) and β-amyrin (2), and the flavonoids quercitrin (3) and isoquercetin (4), were isolated from the leaves. The branches afforded the triterpene arjunolic acid (5). The antinociceptive activity of crude extract, fractions and compound 5 were tested using the writhing and formalin tests in mice. The crude extract, some fractions, particularly dichloromethane and butanol (leaves), ethyl acetate (branches) and arjunolic acid (5) (81.2% inhibition) were more active against the writhing test than the two reference drugs, acetylsalicylic acid and indomethacin.

Constituintes químicos do caule de Senna reticulata Willd. (Leguminoseae): Chemical constituents isolated from the wood of Senna reticulata Willd.

The phytochemical investigation of the wood extracts of Senna reticulata (Leguminoseae) yielded six anthraquinones: chrysophanol, physcion, aloe-emodin, 1,3,8-trihydroxyanthraquinone, 3-methoxy-1,6,8-trihydroxyanthraquinone, emodin and the chrysophanol-10,10' bianthrone. The triterpenes a and b-amirin, the steroids b-sitosterol and stigmasterol as well as the flavonoid kaempferol were also identified. The structures were established by spectral analysis, including two-dimensional NMR techniques. It is the first report of 1,3,8-trihydroxyanthraquinone and 3-methoxy-1,6,8-trihydroxyanthraquinone in higher plants.

Avaliação da pós-graduação da área de química na CAPES e a internacionalização das revistas da Sociedade Brasileira de Química: Journal of the Brazilian Chemical Society e Química Nova

This paper discusses of the use of the Impact Factor in the evaluation of chemistry graduate courses by CAPES and the internationalization of the Journal of the Brazilian Chemical Society and Química Nova.

Productivity, Technical eficiency and internationalisation of the Spanish chemical sector

relationship between productivity and international position of Spanish chemical firms in the period 2005-2011. The goal is to determine whether companies that follow and international strategy, either with exports or by investment in foreign countries obtain greater productivity growth than these that do not operate in global market. For this purpose a panel data set with microdata has been created. A preliminary analysis of the evolution of productivity growth in the sector is carried out. The measurement of Total Factor Productivity is performed. With the estimated TFP we analyze the differentials in productivity growth, comparing the effects of export and investment behavior with non-international firms.

Biofouling e biodeterioração química de argamassa de cimento portland em reservatório de usina hidroelétrica

Last decade Brazilian rivers experimented progressive biofouling of Limnoperna fortunei communities and Cordylophora caspia hydroids. The microhabitat is so favorable that in around 1.5 years L. fortunei increased from 0.39 to nearby 149,000 units/m². Ten Portland cement mortar samples were produced with 1: 3.5: 0.4 dosages and installed for 1 year at Salto Caxias Brazilian Power Plant reservoir in 0.5 m and 1.0 m deep to investigate the biofouling influence on hydraulic civil structures. SEM, EDS, visual investigation and XRF results indicate none direct chemical interrelationships between L. fortunei and the mortar samples. However C. caspia diminished the mortar surface resistance and caused cement paste leaching.

Chemical composition and antibacterial activities from the essential oils of myrtaceae species planted in Brazil

The essential oils of seven Myrtaceae species were investigated for its chemical composition and antibacterial activity. The volatile oils were characterized by a high content of monoterpenoids of which 1,8-cineole (88.0, 65.0 and 77.0% for Melaleuca hypericifolia, Callistemon viminalis and Callistemon citrinus respectively), terpinen-4-ol (47.0 and 49.8% for Melaleuca thymifolia and Callistemon polandii respectively) and α-pinene (54.5% for Kunzea ericoides) were the major components. The oil from M. linariifolia was characterized by a high concentration of methyleugenol (87.2%). The oil from Melaleuca thymifolia was the most active, exhibiting high antimicrobial activity against all tested bacteria.

pH effect on the synthesis of magnetite nanoparticles by the chemical reduction-precipitation method

This work aimed at putting in evidence the influence of the pH on the chemical nature and properties of the synthesized magnetic nanocomposites. Saturation magnetization measurements evidenced a marked difference of the magnetic behavior of samples, depending on the final pH of the solution after reaction. Magnetite and maghemite in different proportions were the main magnetic iron oxides actually identified. Synthesis with final pH between 9.7-10.6 produced nearly pure magnetite with little or no other associated iron oxide. Under other synthetic conditions, goethite also appears in proportions that depended upon the pH of the synthesis medium.